Failure Mode and Effect Analysis (FMEA) and Failure Mode, Effects & Criticality Analysis (FMECA)
These are methods used to identify, describe and examine potential failures in a system, equipment / product or process. The purpose of the analysis is to identify parts or characteristics of the system, which should be improved in order to meet predefined requirements to safety or reliability. It uses Risk Priority Number (RPN), a combination of Severity, Occurrence and Detection/ Effectiveness, as a measure to help identify critical failure modes associated with design or process. It helps in development of a criticality ranking for each failure mode, which provides the basis for establishing preventive maintenance and sparing philosophies as well as redundancy configurations.
Reliability, Availability and Maintainability (RAM) Modelling
Concepts have been widely used by operators to develop optimised production solutions which minimise impact on revenue and expenditure. Reliability, Availability & Maintainability (RAM) modelling assesses a production system’s capabilities in operation or design phase. RAM simulate the configuration, operation, failure, repair and maintenance of equipment using physical components, equipment configuration and maintenance philosophy in a system as inputs. The results from a RAM modelling will identify possible causes of production losses and can examine possible system alternatives. It is used as decision-making tool with help for costs versus benefits analysis
Safety Lifecycle Management
The integrity of a facility/ system can be evaluated in terms of the adequacy of its control measures and safeguards in place. SIL is a measure of safety system performance, or probability of failure on demand (PFD) for a Safety instrumented Function (SIF) or Safety Instrumented System (SIS). Safety Integrity Level (SIL) assessment determines the effectiveness of safety systems based on the probability of tolerable incidents that can occur within a number of processing demands. SIL Assessment is covered in two phases i.e. SIL Classification to determine the target SIL level based on Risk Matrix, Risk Graph or LOPA approach and SIL Verification to verify the SIL levels of SIF/SIS based on the Probability of failure on demand (PFD) for each of the component.
Layer of Protection Analysis (LOPA)
LOPA is a powerful analytical tool for assessing the adequacy of protection layers used to mitigate process risk. LOPA builds upon well-known process hazards analysis techniques, applying semi-quantitative measures to the evaluation of the frequency of potential incidents and the probability of failure of the protection layers. Typically LOPA is used to evaluate scenarios that have been identified in a prior hazard identification exercise usually HAZOP.